Illustration of renewable energy sources obscured by dark clouds, representing a renewable energy shortage.

Decoding Dunkelflaute: How to Navigate Renewable Energy Shortages

Soraya Malik in Climate & Environment December 2025 • 3 min read.

"A comprehensive guide to understanding, analyzing, and preparing for periods of low renewable energy availability in a sustainable future."

As the world increasingly embraces renewable energy sources, understanding the challenges that come with them becomes paramount. Among these challenges, periods of low renewable energy availability, often referred to as "Dunkelflaute" (German for 'dark doldrums'), are gaining significant attention. These periods, characterized by a shortage of wind and solar energy, can pose substantial risks to energy security and grid stability.

Defining, quantifying, and comparing these shortage events across different renewable generation technologies and geographical locations is a surprisingly intricate challenge. Various methodological approaches exist in different bodies of literature, which have been applied to single technologies in specific locations or technology portfolios across multiple regions.

This article provides a clear and accessible guide to navigating the complexities of renewable energy shortages. We'll explore the various methods for quantifying these events, focusing on both the supply of variable renewables and the mismatch with electricity demand. By understanding the merits and challenges of different approaches, we can pave the way for more accurate shortage determination and ensure a sustainable energy future.

What is Dunkelflaute and Why Does it Matter?

Illustration of renewable energy sources obscured by dark clouds, representing a renewable energy shortage.

Dunkelflaute refers to periods when the output from wind and solar power generation is significantly reduced due to unfavorable weather conditions. This can happen during times of calm winds, overcast skies, or even during winter months when daylight hours are shorter. These conditions can persist for days or even weeks, creating a challenge for energy systems that rely heavily on renewable sources.

The increasing reliance on variable renewable energy (VRE) sources like wind and solar makes understanding and managing Dunkelflaute events critical. Without proper planning and mitigation strategies, these shortages can lead to:

Increased reliance on fossil fuels to fill the gap, undermining climate goals.
Price spikes in electricity markets, impacting consumers and businesses.
Grid instability and potential blackouts, jeopardizing energy security.
Delays in the transition to a fully decarbonized energy system.

Therefore, effectively analyzing and addressing Dunkelflaute is not just an academic exercise but a crucial step towards building a reliable, sustainable, and affordable energy future.

Towards a Resilient Renewable Energy Future

Understanding and addressing VRE shortage events like Dunkelflaute is not merely a technical challenge but a fundamental requirement for achieving a sustainable and reliable energy future. By harmonizing terminologies, unifying methodologies, and embracing comprehensive analytical approaches, we can effectively navigate the complexities of variable renewable energy and ensure a future powered by clean, secure, and affordable energy.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1088/2753-3751/ad6dfc,

Title: Measuring The Dunkelflaute: How (Not) To Analyze Variable Renewable Energy Shortage

Subject: econ.gn q-fin.ec

Authors: Martin Kittel, Wolf-Peter Schill

Published: 09-02-2024

Everything You Need To Know

What is Dunkelflaute and how does it impact renewable energy systems?

Dunkelflaute, a German term meaning 'dark doldrums,' refers to periods of low renewable energy availability, specifically a shortage of wind and solar power. This occurs due to unfavorable weather conditions like calm winds, overcast skies, or short daylight hours, potentially lasting days or weeks. Its impact is significant: it can lead to increased reliance on fossil fuels, price spikes in electricity markets, grid instability, potential blackouts, and delays in transitioning to a decarbonized energy system. Effectively addressing Dunkelflaute is crucial for ensuring a reliable, sustainable, and affordable energy future powered by Variable Renewable Energy (VRE) sources.

Why is understanding and managing Dunkelflaute so important as we move towards renewable energy?

As the world increases its reliance on Variable Renewable Energy (VRE) sources such as wind and solar, understanding and managing Dunkelflaute becomes paramount. The periods of low renewable energy availability, caused by events like calm winds or overcast skies, pose substantial risks. Without proper planning and mitigation strategies, Dunkelflaute events can undermine climate goals by increasing reliance on fossil fuels, cause price spikes, destabilize the grid, and delay the shift to a fully decarbonized energy system. Addressing Dunkelflaute is thus essential for a reliable, sustainable, and affordable energy future.

What are the primary challenges in analyzing Dunkelflaute events?

Defining, quantifying, and comparing Dunkelflaute events across different renewable generation technologies and geographical locations presents intricate challenges. There isn't a single, universally accepted methodology. Various methodological approaches exist, applied to single technologies in specific locations, or technology portfolios across multiple regions. Harmonizing terminologies and unifying methodologies is crucial for accurate shortage determination and a sustainable energy future.

How can we build a more resilient renewable energy future in the face of Dunkelflaute?

Building a resilient renewable energy future requires understanding and addressing Variable Renewable Energy (VRE) shortage events like Dunkelflaute. This goes beyond a mere technical challenge; it's fundamental to achieving a sustainable and reliable energy future. The key lies in harmonizing terminologies, unifying methodologies, and embracing comprehensive analytical approaches. By doing so, we can effectively navigate the complexities of VRE and ensure a future powered by clean, secure, and affordable energy.

What are the potential consequences of not addressing Dunkelflaute in the context of renewable energy adoption?

Failing to address Dunkelflaute carries several significant consequences. Increased reliance on fossil fuels to compensate for the shortage of wind and solar energy undermines climate goals. Consumers and businesses may face price spikes in electricity markets. Grid instability and potential blackouts could jeopardize energy security. Moreover, it could delay the transition to a fully decarbonized energy system. Effectively managing Dunkelflaute is, therefore, a crucial step towards a reliable, sustainable, and affordable energy future.